Mandrel for springs



(No Model.)

P. N. FRENCH. I

MANDREL FOR SPRINGS.

No.349,42'7. Patented se t.21, 13a6.

wrmsss ss: INVFNTQR, W /%M%M/ Nv PETERS. Pmwwm m Washington. 0. c.

UNITED STATES PATENT OFFICE.

' PHILO N. FRENCH, OF PITTSBURG, PENNSYLVANIA.

MANDREL FOR SPRINGS.

$ PECIFICATION forming pan. of Letters Patent No. 349,427, dated September 21, 1886.

Application filed June 19, 1886. Serial No. 205.732. (No model.)

To aZZ whom it may concern.-

Be it known that 1, Palm N. FRENCH, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented or discovered certain new and useful Improvements in Mandrels for Springs, of which improvements the following is a specification.

In the accompanying drawings, which form a part of this specification, Figure 1 is a View in side elevation of an ordinary spring-coil machine havingmyimproved mandrel mounted therein. Fig. 2 is a view in elevation of the mandrel and its supporting-arbor. Fig. 3' is a view in elevation of the mandrel on an enlarged scale.

In forming keg-shaped springs-i e.,.tapering from the center to the ends-the practice is to coil the spring on an iron or steel mandrel, cylindrical from one end to the center and tapering from the center to the opposite end. The spring thus formed is then removed from the mandrel, and the coils at the end formed on the cylindrical part of the mandrel, after being properly heated, are beaten down, as it is termed, by hand, to produce the desired taper at that end of the spring.

The invention herein relates to certain improvements in mandrels for forming keg and other irregularly shaped springs, whereby such springs may be wound entirely 011 the mandrel, thereby dispensing with the handwork now necessary; and to this end the invention consists in the construction substan- Stantially as hereinafter described and claimed.

The difliculty heretofore experienced in the manufacture of springs larger at the center than at the ends consisted in the impossibility of removing the mandrel from a completed spring; hence the necessity of partially forming the spring by hand. To avoid the expense incident to the old method, I now propose to form the mandrel-1 of wood or other easily-'destructible material.

In coiling springs with my improved device the mandrel is first formed in any desired shape by turning from a block of wood, preferably of a hard close fibered nature. This mandrel, through which a hole is bored, is then slipped onto the arbor 2, and the end of the arbor then placed in the revolving heads 3 and 4, the latter being mounted in a journal-block, 5, constructed to slide upon bars 6, arranged longitudinally of the bed of the machine. The block 5 is moved back and forth on the bars 6, to insert and remove the arbor, by the lever 7 and toggle-bars S,the revolving heads 3 and 4 being provided with sockets for the reception of the squared ends of the arbor 2. I

On the,bed of the machine is mounted a carriage, 9, for the holding and guiding of the bar or rod during the coiling operation, said carriage being moved along the bed by the screw 10, which is rotated by suitable gearing or bar is passed through a suitable guide in the carriage 9 and inserted between the arbor and the dog 11, secured to the head 4. Power isthen applied to the -head 3, to rotate the same, and with it the arbor and head 4, thereby wrapping the rod around the man drel, which fits sufliciently tight on the arbor to rotate therewith. As the coiling proceeds the carriage 9 is moved along the bed, thus distributing the coils along the mandrel, the rapidity of movement of the carriage determining the pitch of the coils. After the rod has been coiled on the mandrel the arbor is removed from the heads and the mandrel forced oft the arbor. The mandrel, with the rod or bar coiled thereon, is then placed in a furnace and the mandrel burned out, leaving a perfectly-coiled spring, ready for the finishing operation.

In lieu of wood, any other suitable material.

PHILO N. FRENCH. Witnesses:

R. H. WHITTLESEY,

O. M. CLARKE. 

